Abstract: An upstacking device is shown for use with generally flat metal can ends. The device is used with an endless conveyor such as a transport belt having openings therein, with each opening receiving a shell for locating the shell on the belt. The belt is intermittently advanced. The upstacking device includes a drive input coupled to a main drive for producing reciprocating rotational motion. A drive shaft is rotationally mounted to the frame. A stacking arm is fixedly connected to the drive shaft so that reciprocating rotation of the shaft produces rising and falling motion of the distal end of the arm. Stack pistons are pivotally connected to the stacking arm and have can end engaging surfaces. The drive shaft, stacking arm and pistons are positioned such that (a) whenever the stacking arm is in a lowered position, the shell-engaging surfaces are positioned below the belt, and (b) the pistons are aligned with the openings for movement therethrough.